Attic Lift System

Abstract

An attic lift system is provided, comprising a loading platform attached to a lifting frame having a plurality of vertical frame members, wherein the lifting frame includes a closure member positioned below the loading platform. The closure member includes a plurality of telescopic guide members, wherein the support frame is positioned on an attic floor above an opening in the attic floor. A plurality of support rods extend from the closure member and are threadably engaged with the vertical frame members of the lifting frame. A drive assembly is positioned on the support frame and connected to the lifting frame for raising and lowering the loading platform relative to the opening. Limit switches are present to detect when the drive assembly should be stopped based on the position of the lift platform.

The invention claimed is: 
     
         1 . An attic lift system for lifting and lowering a loading platform between a room having a room floor and a ceiling to an attic having an attic floor, comprising:
 a loading platform attached to a lifting frame having a plurality of vertical frame members, wherein the lifting frame includes a closure member positioned below the loading platform and separated from the loading platform by a fixed distance, wherein the fixed distance is approximately equal to the difference in height between the ceiling of the room and the attic floor; and wherein the loading platform includes openings for loading and unloading from all sides of the loading platform;   a plurality of telescopic guide members connected to the closure member and a support frame, wherein the support frame includes openings for loading and unloading from all sides of the support frame, and wherein the support frame is fixed to the attic floor above an opening in the attic floor;   a plurality of support rods extending from the closure member and threadably engaged with the vertical frame members of the lifting frame, wherein the fixed distance between the loading platform and the closure member can be adjusted to approximate the difference in height between the ceiling of the room and the attic floor;   a drive assembly positioned on the support frame and operatively connected to the lifting frame for raising and lowering the loading platform relative to the opening; and   a first limit switch operatively positioned on the closure member and in electrical communication with the drive assembly, for detecting when the closure member is adjacent to the room floor, and causing the drive assembly to stop lowering the loading platform.   
     
     
         2 . The system of  claim 1 , wherein the drive assembly comprises a motor and winch having a tether connected to the lifting frame. 
     
     
         3 . The system of  claim 1 , wherein each of the vertical frame members is a member which includes an internally threaded nut adapted to receive one of the support rods from the closure member. 
     
     
         4 . The system of  claim 1 , wherein the telescopic guide members are adapted to minimize lateral movement of the loading platform. 
     
     
         5 . The system of  claim 1 , wherein the support rods are adjusted sufficient to cause the loading platform to be flush with the attic floor when the lift system is in a fully raised position. 
     
     
         6 . The system of  claim 1 , further comprising a second limit switch positioned adjacent to the drive assembly and adapted to detect when the lifting frame reaches an upper limit corresponding to closure of the opening by the closure member, and to cause the drive assembly to stop raising the loading platform. 
     
     
         7 . The system of  claim 1 , wherein the support rods are adjusted sufficient to cause the closure member to contact the ceiling and fully close the opening when the lift system is in a fully raised position. 
     
     
         8 . The system of  claim 1 , further comprising a remote switch above the attic floor for controlling the operation of the drive assembly. 
     
     
         9 . The system of  claim 1 , further comprising a wall mounted switch below the ceiling for controlling the operation of the drive assembly. 
     
     
         10 . The system of  claim 9 , further comprising a key lock-out device in communication with the wall mounted switch to prevent unauthorized operation of the drive assembly.